the mind > emotion > love > friendliness > social intercourse or companionship > [noun] > quality of being a good fellow > good fellow or sport (2)
A person concerned with or interested in sport; a sportsman or sportswoman. A fair-minded, generous, or sportsmanlike person; a lively, sociable…
Without specifying word (esp. as the boys). colloquial. Members of a group sharing common (typically masculine) interests; one's (male) fellows…